Method For Separating Disks

ABSTRACT

Disks stuck together in a stack are separated by placing the disks on a shaft of a vibratory apparatus and vibrating the shaft to vibrate the disks by contact of the disks with the vibrating shaft to separate them and also constrain the disks with the shaft as the disks are vibrated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/366,479 filed on Dec. 6, 2012. U.S. Ser. No. 13/366,479 claims thebenefit of U.S. Provisional Application No. 61/440,931, filed on Feb. 9,2011. The entire disclosures of the above applications are incorporatedherein by reference.

FIELD

The present invention relates to separating parts that are stucktogether.

BACKGROUND

In some manufacturing processes, parts may be processed during someoperations and later be separated prior to use of a part in a product.These operations where the parts are processed together may result inthe parts becoming stuck together. They may for example become stucktogether in a stack after being stacked together and heat treated wherethe heat treating results in the parts being stuck together in thestack.

The parts must then be separated before being subsequently used such asin making a product that includes one or more of the parts. A typicalmethod of separating parts stuck together such as in a stack of partshas involved hitting the stack of parts with a force sufficient to causethe parts to break apart from each other. For example, hitting the stackof parts with a rubber mallet, knocking the stack against a surface suchas a table, or the like. Among others, this method presents ergonomicand scrap issues.

Some products are made, at least in part, by laminating. That is, aplurality of laminations are secured together. For example, stators usedin electric motors are often made of laminations secured together. Thelaminations may be stamped from a sheet of ferromagnetic material, suchas ferromagnetic steel or iron. Once the laminations for a stator arestamped, they are stacked (if not already stacked from the stampingoperation), and heat treated. In this regard, the stack of laminationsmay include laminations for multiple stators. It should be understoodthat laminations may also be stuck together in a stack as a result ofmanufacturing processes other than heat treating and need to beseparated before being laminated together. The laminations are thenseparated from each other by the application of manual force asdescribed in above. In addition to the ergonomic and scrap issues thatthis method can present, it can cause some degradation in theferromagnetic properties of the laminations

SUMMARY

In accordance with an aspect of the present disclosure, parts stucktogether in a stack are separated by placing the parts in a vibratoryapparatus and vibrating the stack of parts with a vibratory head of thevibratory apparatus to separate them and also constrain the parts withthe vibratory head as the parts are vibrated.

In an aspect, the parts are laminations stacked together in a stack oflaminations and vibrating the stack of laminations includes contactingthe stack of laminations with a tool of a vibratory head of thevibratory apparatus that is vibrating to vibrate the parts and alsoconstraining the parts with the tool as it vibrates the parts.

In an aspect, the stack of laminations is positioned on its side in thevibratory apparatus and a side of the stack of laminations is contactedwith the tool.

In an aspect, the vibratory apparatus has a table having an anvilmounted therein on which the stack of laminations is positioned. Thestack of laminations is positioned on its side on the anvil. A face ofthe anvil that contacts the stack of laminations has a series of edgesrunning longitudinally therealong with each edge extending laterallyacross the anvil face. The edges grab the individual laminations whenthe stack of laminations is being vibrated to facilitate separation ofthe laminations. In an aspect, the series of edges is a series ofserrations. In an aspect the series of serrations are saw toothserrations. In an aspect, the series of edges is provided by the face ofthe anvil being knurled.

In an aspect, alternatively or in addition, the tool of the vibratoryhead has a series of edges running longitudinally therealong with eachedge extending laterally across the tool face with the edges of the faceof the tool grabbing the laminations when the stack of laminations isbeing vibrated to facilitate separation of the laminations.

In an aspect, the parts are a stack of disks stacked together. The stackof disks are placed in a vibratory apparatus and vibrated with a tool ofa vibratory head of the vibratory apparatus and also constrained withthe tool. In an aspect, the disks have a central bore. In an aspect, thetool has a shaft and placing the disks in the vibratory apparatusincludes placing them on the shaft with the shaft extending through thecentral bores of the disks. Vibrating the disks includes vibrating thevibratory head to vibrate the shaft which vibrates the disks placed onthe shaft.

In an aspect, the vibratory head vibrates at a frequency in the range of60 Hz-320 Hz.

In an aspect, the vibratory head vibrates at ultrasonic frequencies. Inan aspect, vibratory head vibrates at a frequency in the range of 10 kHzto 60 kHz.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 shows a stack of laminations in a vibratory apparatus inaccordance with an aspect of the present disclosure;

FIG. 2 shows an anvil tool for the vibratory apparatus of FIG. 1; and

FIG. 3 shows another anvil for the vibratory apparatus of FIG. 1;

FIG. 4 shows a stack of disks in a vibratory apparatus in accordancewith an aspect of the present disclosure; and

FIG. 5 shows a stack of disks in a vibratory apparatus in accordancewith a variation of the aspect of FIG. 4.

DETAILED DESCRIPTION

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

FIG. 1 shows a lamination stack 10 of laminations 12 positioned on itsside in a vibratory apparatus 100. Lamination stack 10 is made up of anumber of individual laminations 12 (only three of which are identifiedwith lead lines to reference number 12) that are stacked together. Whenfor example the laminations 12 are used to make stators for electricallymotor, laminations 12 are heat treated after they have been stackedtogether in lamination stack 10. Due to the heat treatment, laminations12 stick together as discussed above. It should be understood thatlaminations are used to make products other than stators for electricmotors and can stick together in a stack for reasons other than heattreatment. Vibratory apparatus 100 may illustratively be an apparatussimilar to a vibration welder, such as those described in U.S. Pat. No.3,920,504 to Show et al. for “Friction Welding Apparatus,” and U.S. Pat.No. 4,352,711 to Toth for “Friction Welding Apparatus,” modified asdiscussed below.

Vibratory apparatus 100 includes a vibratory head 102 which mayillustratively have a tool 104 that contacts a side 14 of laminationstack 10, thus contacting the individual laminations 12 and alsoconstraining them as they are vibrated. Cylinders 106, which may behydraulic, electric or pneumatic, are mounted on a base plate 108 andattached to a table 110.

In the illustrative embodiment shown in FIG. 1, lamination stack 10 ispositioned on its side on table 110. Cylinders 106 move table 110against vibratory head 102. Lamination stack 10 is pushed againstvibratory head 102 with a force that is sufficient so that vibratoryhead 102 can vibrate lamination stack 10 to separate laminations 12 aswell as constrain them, but is not sufficient to weld them together. Itshould be understood that vibratory apparatus 100 could alternatively beconfigured so that table 110 remains stationary and vibratory head 102lowered to bring tool 104 into contact with side 14 of stack 10. Itshould also be understood that vibratory apparatus 100 could beconfigured so that lamination stack 10 is contacted by vibratory head102 from a direction other than above stack 10, such as by way ofexample and not of limitation, from below stack 10.

An anvil 112 is mounted to top 114 of table 110, and may be recessedtherein. Anvil 112 has a face 116 having a series of edges 118 spacedlongitudinally therealong. Each edge 118 extends laterally across anvilface 116 as best shown in FIG. 2.

When lamination stack 10 is positioned on anvil 112, it extendslongitudinally along anvil face 116 and edges 118 of anvil face 112extend laterally across lamination stack 10. In the illustrativeembodiment, each lamination 12 is annular (or quasi annular) andlamination stack 10 is thus cylindrical (or quasi cylindrical). Edges118 thus extend across lamination stack 10 perpendicular to alongitudinal axis of lamination stack 10. When lamination stack 10 isvibrated by vibratory head 102, edges 118 will catch in gaps betweenedges (such as by projecting into the gaps) of adjacent laminations 12in lamination stack 10 and in effect grab the laminations 12, whichfacilitates the separation of the laminations 12. This also has theeffect of rifling the laminations 12 thus facilitating their separation.

The series of edges 118 may illustratively be a series of serrations,which may illustratively be a series of saw tooth serrations as shown inFIG. 1. The series of edges 118 may illustratively be provided by anvilface 116 having a knurled surface 300 as shown in FIG. 3. It should beunderstood that the foregoing are examples and are not exhaustive of howedges 118 may be provided. In this regard, edges 118 can be provided byforming anvil face 116 in any manner that provides edges that willengage with laminations 12 of stack 10, such as by projecting into gapsbetween edges of adjacent laminations 12. In this regard, it should beunderstood that each edge need not be a continuous edge but could forexample be a series of points, fingers or the like, and may be providedby tool face 116 having a roughened surface.

It should be understood that the edges 118 may illustratively bedetermined based on the geometry of the laminations 12 in laminationstack 10 so that edges 118 optimally engage with the laminations 12 instack 10. For example, the spacing of the edges 118 in anvil face 116may illustratively correspond to the thickness of the laminations 12.That is adjacent edges 118 are spaced from each other a distance that isthe same as the thickness of a lamination 12.

Tool 104 of vibratory head 102 may also include similar edges (tool112′, as shown in phantom in FIG. 1).

Illustratively, vibratory head 102 vibrates in the range of 60 Hz-320Hz. It should be understood that these frequencies are exemplar and thatvibratory head 102 can vibrate at other frequencies. In this regard, theoptimum frequency can for example be heuristically determined and maydiffer depending the laminations and the degree to which the laminations12 in lamination stack 10 stick together after heat treating.

It should also be understood that vibratory apparatus 100 could also bean ultrasonic vibratory apparatus, such as an ultrasonic welder,modified so that the horn of the ultrasonic apparatus, which wouldcomprise vibratory head 102, contacts lamination stack 10 withsufficient force to vibrate the laminations 12 loose from each other aswell as constrain them, but not enough force to weld them. A prior artultrasonic welder that could be modified in this regard is disclosed inU.S. 2008/0054051 for Ultrasonic Welding Using Amplitude Profiling. Inaccordance with an aspect of the present disclosure, the vibratory headwould illustratively vibrate at a frequency of about 10 kHz to 60 kHz.

Separating the laminations in a stack of laminations by contacting thestack with a vibratory head in accordance with the above (which may bereferred to as “vibratory separated laminations”) enhances theefficiency of the electric motor having a stator made with the vibratoryseparated laminations. Since the laminations in the stack of laminationsare not being separated with the “breaking lam manually” approach, thelaminations are not subjected to the type of abrupt force inherent inthis approach. Thus, there is less degradation of the ferromagneticproperties of the laminations and core loss readings of stators madewith the vibratory separated laminations are improved. Further, byconstraining the parts with the vibratory head as they are beingvibrated reduces the possibility of damaging the parts due to theirbouncing around if unconstrained.

While the foregoing has been described in the context of separatinglaminations in a stack of laminations, it should be understood that avibratory apparatus can be used in accordance with the above to separateother types of parts used in making products where a plurality of theparts are stuck together in some manner and need to be separated beforebeing used to make the products.

As another example and not of limitation, with reference to FIG. 4,disks 400 in a stack 402 of disks 400 can be separated by placing thestack 402 of disks 400 in a vibratory apparatus 404 and vibrating thestack 402 of disks 400. In FIG. 4, vibratory apparatus 404 includes avibratory head 406 having a tool 408. In the embodiment shown, tool 408includes a vertical shaft 410. The stack 402 of disks 400 are placed ontool 408 with vertical shaft 410 extending through central bores 412 ofdisks 400. To separate disks 400 in stack 402, vibratory head 406 isvibrated by vibratory apparatus 404 resulting in shaft 410 vibrating.The disks 400 are in contact with the vibrating shaft 410 and thevibration causes the disks 400 in stack 402 to break apart from eachother. Shaft 410 also constrains disks 400. Disks 400 may by way ofexample and not of limitation be grinding disks.

FIG. 5 shows a variation of FIG. 5 wherein vibratory head 406 (FIG. 4)has tool 500 having a horizontal shaft 502. In the embodiment of FIG. 5,the stack 402 of disks 400 are placed on tool 500 with horizontal shaft502 extending through central bores 412 of disks 400.

While in the above described aspects the stack of parts is constrainedby the tool of the vibratory head contacting one surface of the stack ofparts, it should be understood that the tool can contact more than onesurface of the stack of parts to constrain them. By way of example andnot of limitation, the aspect of FIG. 5, the stack 402 of disks 400 canalso extend across the horizontal shaft 502 and be constrained byopposed brackets 504 that hold horizontal shaft 502.

The description of the invention is merely exemplary in nature and,thus, variations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

What is claimed is:
 1. A method of separating a stack of disks stucktogether, the disks having central bores therein, the method comprisingplacing the disks on a shaft of a tool of a vibratory head of avibratory apparatus with the shaft extending through the central boresof the disk, vibrating the vibratory head with the vibratory apparatusthus vibrating the tool and its shaft to vibrate the disks by contact ofthe disks with the vibrating shaft on which the disks are placed andalso constraining the disks with the shaft as the disks are vibrated bytheir contact with the vibrating shaft.
 2. The method of claim 1 whereinthe shaft is a horizontal shaft and further including constraining thedisks on the shaft with brackets of the vibratory apparatus that holdthe shaft.